1. Field of the Invention
The invention relates generally to electrical connectors and more specifically to mating connectors that include shorting bars to protect the circuits.
2. Discussion of Related Art
Shorting bar systems have been employed on vehicle safety devices such as airbags, seat restraints and ABS brakes. For example, in airbag connectors, the shorting bars short circuit the triggering circuit by shorting the female terminals in the female connector to each other if the connectors are inadvertently disconnected or intentionally disconnected for maintenance or testing purposes. Since these are generally low current components, there can be a buildup of oxidation on the electrical contacts, causing electrical discontinuity in the circuits. Often, in the assembly process, the electrical connections in these safety devices are made by hand because of the fragility of the components and the relative complexity of the assembly process. With the continued automation of automotive assembly lines, modular assembly of these devices has become necessary.
Typically, a mating electrical connector disconnects the short. A female connector housing has female terminals and shorting bars. The shorting bars are shaped and spring biased to be in electrical engagement with the female contacts. A male connector housing has male contacts and engagement posts. When the connector housings are mated, the male contacts are mechanically and electrically connected to the female contacts. The engagement posts of the male connector housing disengage the shorting bars from the female contacts, eliminating the short circuit and making the connector assembly fully operational.
In many cases, oxidation can occur on the shorting bar contact surfaces, affecting the reliability of the short connection with the terminals. The engagement posts are often thin and short, and inaccuracies in length and position caused by the molding process may cause them to miss or ineffectively deflect the shorting bars. In addition, there is typically nothing to protect the mated connectors in vehicle areas such as engine compartments. If they are jostled or collide with other vehicle components, the male and female connectors can shift or vibrate relative to each other. This can damage the terminals and cause them to wear on each other. Fretting corrosion, which occurs when parts of the terminal plating flake off and oxidizing takes place on the exposed terminal surfaces, is not uncommon. However, if the electrical connection process becomes more complex when these problems are addressed, there is a risk that assembly can no longer be automated.
Accordingly, it is an object of this invention to ensure positive contact between male and female terminals in mating connectors prior to disconnect of a safety short, and to ensure the safety short is reconnected before the terminals are unmated.
A further object of the invention is to enable the connector assembly to be axially adjustable as a unit so connectors of the assembly do not move relative to each other.
Another object of the invention is to provide a simple, reliable shorting system for a fully automated modular connector assembly.
In carrying out this invention in the illustrative embodiment thereof, a holder is used to secure a female connector in a first position. The holder has shorting contacts. The female connector has slots through which the shorting contacts engage female terminals within the female connector in the first position. There are cam surfaces at ends of the slots. When a male connector is inserted into the holder, the female connector remains in the first position until the connectors are fully mated with male terminals in the male connector in electrical engagement with the female terminals. Further insertion of the male connector releases the female connector from the first position and locks the connectors together. The connectors move together as a unit to a second position. Simultaneously, the cam surfaces push the shorting contacts out of the slots, enabling functional operation of the connectors. Any forces pushing or pulling on the connectors cause them to move as a unit in an axial adjustable direction within the holder, preventing damage to and reducing wear on the terminals and allowing for manufacturing tolerances, until the connectors are secured in a required position by, for example, locking tabs on the male connector.
When it is desired to break the electrical connection and separate the connectors, the connectors are pulled or pushed back to the first position within the holder. The female connector again becomes locked in the first position by the holder as the shorting contacts reengage the female terminals. Further removal force on the male connector then separates the connectors and takes the male connector out of the holder. Operation of the shorting contacts and holder and connector locks is achieved simply by movement of the connectors axially within the holder, so the assembly and disassembly of the connectors can be fully automated.